Newb lipo storage question

[Dragon51]

Ok I know from searching that you can saftly store lipos at full charge for 2-3 weeks then who knows how long at 50% My question is how do you know when they are at 50%. 3.75-3.8 volts per cell. (Per John rob holmes)
Storing Lipo's between use

For isntance I have a 2s 910mah pack. I have the hyprtion EOS606i charger that I have not ever used yet. Will it let me know when it's at 50% or do I need to get a Voltmetter. It might be a few weeks between runs I hope not but I do have a wife and 21 month old. I don't always have the time.

Also the thunder power pack that I bought has a differn blance plug then the Hypersion balancing adapter does. The hobbie store also said you don't need to balance them?

[JAM MaxAmps.com]

Most of the new current chargers such as the Hyperions depending on model will show what you have put back into a pack in mAH. The DUO even has a storage mode which by the way works great. You 0606i will show you how much your putting back into the pack just watch the screen and shut off whn your at that 50% point. Go by the capacity not the voltage. As for your balance taps you need to buy the Thunder power adapter board seen here: http://www.maxamps.com/proddetail.ph...ULTI-TP&cat=34 and don't listen to your LHS guy Li-po's need to be balanced chraged everytime no matter what brand. The balancer will not only ensure that the pack stays in tip top shape but it also acts as a safety device incase a cell were to try to over charge.

If you have any other questions just ask.

Jason

[nmanuel01]

Ive had lipos for some time and usually store them charged, but use them a bit more often and always charge and balance them.
I have a Dynmaite Ultra Vision Peak that works great for my application, ho do you measure capacity is volts x X?

[Dragon51]

Thank you for the link and the info, it's nice when the LCH tell you a line of crap!

[Dragon51]

Ok well I got that adapter ordered now I have to wait longer to play I was so close too! Looks like I should of kept that brick sub c pack!

[rockhugger]

I searched and found info on safe storing and charging of lipos, and do's and don't about hi temps, but

How does storing them in the cold affect safety and or the life of the battery? I have mine in the shed outside where it's 30 deg or so most of the day, sometimes freezing at night, so how is this going to affect it?

thanks

[JAM MaxAmps.com]

Originally Posted by rockhugger

I searched and found info on safe storing and charging of lipos, and do's and don't about hi temps, but

How does storing them in the cold affect safety and or the life of the battery? I have mine in the shed outside where it's 30 deg or so most of the day, sometimes freezing at night, so how is this going to affect it?

thanks

Wow you really shouldn't be storing them out in the cold like that. Bring them inside and either put them in a fire proof conatiner, bag, ammo box or something. Letting them freeze is not good. There nort going to start a fire just sitting so put them in the basement or a cool dry location away from flamables. Remember a Li-po will only flame if charged incorrectly or dead shorted so there really isn't much to worry about while they sit on your shelf at home. Just make sure to put them at 50 to 60% of the packs capacity if they are going to sit for any long periods of time then cycle them once every 30 days.

Jason

[EeePee]

Not to start anything here but depending what or where you read, you get different answers about cold temps and storage.

Freezer:

http://www.kongpower.com/faq_en/show...xt01=&srhTxt02

Or in the fridge:

http://www.helifreak.com/showthread....01#post1099401

Me, I have some in the freezer, and some in the fridge, and some on the shelf.

[JAM MaxAmps.com]

There was some testing done back over a year ago at RC Groups and they did the whole fridge and cold storage deal. The results proved that it wasn't worth the effort to even bother with the whole cold storage thing. It didn't prolong battery life or anything. I just don't recommend you let packs freeze.

Jason

[rockhugger]

Originally Posted by JAM MaxAmps.com

Wow you really shouldn't be storing them out in the cold like that. Bring them inside and either put them in a fire proof conatiner, bag, ammo box or something. Letting them freeze is not good. There nort going to start a fire just sitting so put them in the basement or a cool dry location away from flamables. Remember a Li-po will only flame if charged incorrectly or dead shorted so there really isn't much to worry about while they sit on your shelf at home. Just make sure to put them at 50 to 60% of the packs capacity if they are going to sit for any long periods of time then cycle them once every 30 days.

Jason

thanks,
I will do the fire proof container inside the toasty warm house -
(65-70deg. most of the time).

the reason I asked was because this past weekend I tried charging my tx pack (7.4-2100 20c lipo) to go run and the charger was stopping (duratrax ICE charger) like the battery was not taking anything. It was charged to 100% maybe a 1-2 months ago then sat on the shelf in the shed (where it is cold) for that time frame.
I was not really sure, and as winter gets colder I became more worried about killing off my expensive batteries by storing them outside.

I will bring them inside after fire proofing the whole house just kidding. Can this battery be brought back or is it a goner?

thanks again.

[JAM MaxAmps.com]

What's the pack voltage at right now after it has warmed up?

Jason

[rockhugger]

Originally Posted by JAM MaxAmps.com

What's the pack voltage at right now after it has warmed up?

Jason

had to go to my friends to test it, but it said .390 volts
I also need to update the battery info it's a 2100 mah 7.4 20c, not that it makes any difference, but I stated it incorectly in my first post.

to check to see for reference,
we also tested a brand new 7.4 lipo pack test right next to it at 7.6 ish.

thanks for the help

[JAM MaxAmps.com]

Yeah that's a dead pack from being frozen. Your not going to recover that one it the total voltage is less than a volt. Chalk that one up to lessoned learned. Don't let Li-Po's freeze.


Jason

[Pdog7]

That is good information. Thanks Jason

[Scottish]

wow i never would have thought to "cold store" these since warning on the back say keep from freezing

[rockhugger]

thanks for the info. It seems as thought the NIMH's have held up fine so far this winter. Probably stick with them here on out.

[Mr.Slave]

so how long can you leave lipos fully charged im just chargin mine up right now and probably wont be running again till nxt weekend
what were to happen? just have to re charge or what?


whats the tollerances for the cells being ballanced?

[JAM MaxAmps.com]

Originally Posted by Mr.Slave

so how long can you leave lipos fully charged im just chargin mine up right now and probably wont be running again till nxt weekend
what were to happen? just have to re charge or what?


whats the tollerances for the cells being ballanced?

A general rule is they can sit with a full charge for up to 3 weeks. I'll let mine sit at a week or so max. Then if anything longer than 3 weeks they should be put at 50-60% of the packs rated capacity and then they should be cycled at least once every 30 days and put back to 50-60% again. As far as charging them back up after they have sat for say a week at full, it's not necessary at all. Li-Po's will drop voltage over time but no where near as fast as a NimH cell does.

Jason

[Mr.Slave]

Originally Posted by JAM MaxAmps.com

A general rule is they can sit with a full charge for up to 3 weeks. I'll let mine sit at a week or so max. Then if anything longer than 3 weeks they should be put at 50-60% of the packs rated capacity and then they should be cycled at least once every 30 days and put back to 50-60% again. As far as charging them back up after they have sat for say a week at full, it's not necessary at all. Li-Po's will drop voltage over time but no where near as fast as a NimH cell does.

Jason

ok cool,
what happens after 3 weeks?

and what are the tolerances for the balanced packs (like cell 1 4.16v, and cell 2 4.20) whats good and whats bad?

thanks for the post jason.

[JAM MaxAmps.com]

For some reason they can have the full charge in them then you use the pack and poof a dead cell shows up. It's a strange thing and it doesn't happen all the time but after a few years of testing from a lot of people it's just been determined better to store them at 50-60% of their rated capacity. Cells should never be more than .5 volts apart if you see more than that most of todays top balancer/chargers will detect this as an error and will not allow you to charge the pack. In most cases if you see a cell out like that it's a sign of that cell slipping .


Jason